This invention relates to soil cultivating apparatus and is especially applicable to apparatus known as subsoilers, in which a cultivating tool or tine penetrates and disturbs the sub-soil layer.
To avoid breakage of a tine in a subsoiler, the mounting of the tine on the main frame of the subsoiler is typically by two bolts, one of which is of smaller diameter than the other so that, on meeting an obstruction which might otherwise damage the tine, the smaller bolt shears, allowing the tine to pivot clear of the obstruction about the larger bolt. In rocky areas of the country, subsoilers have been found to be of limited use, because rocks in the subsoil layer cause repeated shearing of the bolts, requiring frequent stops during the subsoiling operation to instal new shearable bolts. This can lead operators to replace the shearable bolts with stronger bolts in the hope that the tine will then drag aside any, or at least most, obstructions. However, this practice frequently leads to breakage of the tines, and can even lead to damage to the tractor to which the subsoiler is connected.
An object of the invention is to provide soil cultivating apparatus in which the breakage of tines by sub-soil obstructions is avoided.
A further object of the invention is to provide apparatus in which the cultivating tool may readily be re-set to the operating position thereof after displacement from the soil by an obstruction.